Absorption refrigerating apparatus



March 5, 1935. R. s. NELSON ET AL ABSORPTION REFRIGERATING APPARATUS Filed Aug. 14, 1953 imuh aan@ ma a ZM@ 5x Mwdmlm ZZ/W Mm E Patented Mar. 5, 1,935

1,993,381 ABsoRPrIoN REFRIGERATING APPARATUS Rudolph S. Nelson, Rockford, Ill., and Walter C. Davidson, North Canton, Ohio, assignors to The Hoover Company, North Canton, Ohio, a

corporation of Ohio Application August 14,

ma,y serian No. 685,039

This invention relates to absorption refrigerert gas circuit are claimed. Other features of ating apparatus and more particularly for that novelty in the system disclosed aremore fully type which employs an linert gas as a pressure described and claimed in the co-pending applicaequalizing medium.

In continuous operating absorption refrigerating system it is known to employ an inert gas such as hydrogen or air, as a pressure equalizing medium so that the total pressure throughout the entire system is substantially the same. In such systems it is common to circulate the inert gas between the evaporator and the absorber of the tionbf Rudolph S. Nelson, Serial No. 680,749, iiled July 17, 1933. Y

Referring to the drawing in detail it will be seen that the single embodiment of the invention disclosed comprises a continuous absorption refrigerating system having a boiler B, a gas-separation chamber S, a main condenser C, an evaporator E, an absorber designated generally as A,

system under the infiuence of the force of gravity and Various Connecting conduits and Darts Whieh and as the result of heating and cooling certain portions of the gas circuit.

It is the object of the present invention to provide improved `means for circulating the inert gas between the evaporator and the absorber of a continuous absorption refrigerating system f the class mentioned above, and to improve the enigo to make up Ythe complete system.

A small conduit 11 connects the boiler B to theuper portion of the gas separating chamber S, this conduit acting as a gas lift pump to convey absorption liquid into the chamber S in accordance with,known practices. 'I'he gas passes from the chamber S ciency of the system as a whole by the transfer of threugh the ,Conduit 12 t0 the Condenser C- -As `heat from one part to another.

It is the further object of the invention to provide asrigid construction'of an absorption unit designed to be fitted into a refrigerator cabinet of the ordinary household size and in which certain portions of the conduitsy which make up the inert shown in Figure 1, the. lower portion of the conduit 12 is `of smaller `diameter than the upper portion and this lower portion passes through a gas conduit 13. This gas conduit 13 is of an inverted U-shape, having an upper horizontal portion which extends across the entire unit, and two gas circuit may be utilized as a frame-work-for depending legs. It thiis constitutes a freine OI' supporting otherparts of the system.

It is the further object of the invention to so construct certain portions of the conduits which make up the inert gas circuit as to permit them to be imbedded in a portion of the wall or the insulation of the refrigerator cabinet so that the space occupied by the system may be reduced to a minimum. i

Other objects and advantages reside in certain novel features of the arrangement and construction of parts as will be apparent from a consideration of the following description taken in connection with the accompanying drawing in which;

` Figure 1 is a view in elevation of a continuous absorption refrigerating system constructed in accordance with the present invention, certain parts having been broken away to illustrate the construction;

Figure 2 is a diagram illustrating themanner in which the parts are connected in the arrangement of Figure 1;

Figure 3 is a vertical cross-sectional view of a fragment of the unit of Figure 1, the view being taken on the lines 3 3 of Figure l, and showing, in addition, how a part of the unit may be mounted in a wall of a cabinet.

In the present application onlythose features of the apparatus illustrated which relate to the insupporting the main condenser C and a small auxiliary condenser which will be described hereinafter. The main condenser C consists merely of a coil of oval shape which extends across the unit being of about the same length as the upper horizontal portion of the conduit 13. Y The entire condenser C may be supported on the gas pipe 13 by means of braces or cleats such as are indicated at 14 these being welded to the pipe 13 and to the various turns of the condenser coil. The condenser may have one or more coils above the horizontal portion of the gas conduit 13 as well as the number of coils below this portion. In the drawing one coil isv shown above the conduit 13 and the remainder below.

'I'he lower or outlet end of the condenser is connected to a small vessel 15 adapted to receive the liquid refrigerant and also any inert gas which may have found its way into the condenser. The inert gas collected in the vessel 15 passes upwardly through the conduit 16 back into the gas pipe 13. The liquid refrigerant passes downwardly from the vessel 15 through a U-shaped conduit 17 which enters the bottom of the gas heat exchanger and passes through it up to the top of Y disposed cylinder (Figure 3) near the lower end of the cylinder 18 provides a compartment 23 at the lower end, and a larger compartment 24 at the upper end. The gas conduit 25 connects `the lower end of the evaporator to the upper chamber 24. Bailie memyber 26 is located just beneath thepoint of entrance of the conduit 25 into the cylinder 18 and causes gas entering in the lower end, of compartment 24 to pass clear to the top of this compartment before again passing downwardly and entering the gas conduit 25.

As shown in Figure 3 the gas heat exchanger may be entirely enclosed in the insulating wall of the refrigerator cabinet. In the construction illustrated the main wall 27 of the cabinet is recessed to provide space for the heat exchanger, and an insulating slab or cover 28 is provided, which nts snugly around the gas heat exchanger.

During normal operation, the gas heat exchanger operates at a temperature which is approximately the same as that on the interior of the refrigerator cabinet. Hence there is substantially no heat leakage from the food storage compartment of the cabinet on account of the location of the gas heat exchanger in the Wall thereof.

Lower compartment 23 of the gas heat exchanger is connected by means of conduit 21 to the evaporator and, by means of a conduit 30 to the absorber. A gas conduit 31 connects the lower portion of the compartment 24 of the gas heat exchanger to the top of the absorber.

As more fully described in the co-pending application of Rudolph S. Nelson, Serial No. 680,749, led July 17, 1933, the absorber consists of three parts designated 32, 33 and 34 respectively. The part 32 consists of a number of horizontal pipes connected at alternate ends by short slightly inclined pieces. The lower end of this section is connected to a small vessel 35 which is in turn connected by a short vertical pipe 36 to the lower end of the lower section 34. The section 34 also consists of a number of horizontal pipes connected by short laterally extending pieces. The upper end of the lower section 34 is connected to the left-hand leg (as viewed in Figures 1 and 2) of the inverted U-shaped conduit 13 while the right-hand leg of this conduit 13 is connected to the top of the intermediate section 33 of the absorber. The section 33 consists of a vertically disposed cylinder or tank having baille plates 37 in the upper portion thereof. At a point just opposite the lower baille plates 37 of the tank, 33 the gas conduit 30 is connected.

For supplying weak absorption liquid to the obsorber and for removing strong absorption liquid therefrom conduits 38 and 39 are provided. As noted above absorption liquid is lifted by the gas lift conduit 11 into the gas separating chamber S. It flows from there through the conduit 38 downwardly to the heat exchanger 40 and then upwardly to the top of the upper section 32 of 'the absorber. A conduit 41 conveys the absorption liquid from the vessel 35 at the lower end of the section 32 into the gas conduit connected l to the top of the intermediate section 33. After the solution trickles downwardly over the baie plates 37 therein it is collected on the lower baffle plate and drained by the conduit 42 into they l upper pipe of the lower section 34 of the absorber.

The lower end of this section 1s connected by means of the conduit 43 back into the tank 33 the lower portion of which acts as a reservoir. The .conduit 39 conveys absorption liquid from the reservoir back to the boiler, this conduit also passing through the heat exchanger 40. (In the diagram of Figure 2 the conduits 38 and 39 are merely shown in heat exchange relation at the point 40.)

Means for indirectly cooling the intermediate section 33 of the absorber is provided. This consists of a small auxiliary condenser vhaving a number of horizontal conduits designated 45 and a lower conduit 46 which is olfasomewhat larger diameter than the upper conduit. The horizon- `tally extending conduits 45 are all connected to such as are indicated at 47 (Figure 1) all joined to the lower conextends downwardly from headers and these headers are duit 46. A conduit 49 the right-hand side of the conduit 46 and then and this conveys the remainder of the liquid up into the lower pipe 46 of the auxiliary condenser.

The refrigerant gas passes into the upper conduits 45 of the condenser where it is liquefied and joins the unevaporated liquid which has been cooled in the pipe 46 so that both portions of the cooling fluid flow downwardly in the right hand leg of the conduit 49 back to the bottom of the intermediate section 330i the absorber. It will thus be seen that the indirect cooling system for the section 33 is entirely independent of the remainder of the unit.

The auxiliary condenser is supported upon the inverted U-shaped pipe 13 by means of bars 14 like those supporting the main condenser C.

Assuming that the 'main refrigerating portion of the apparatus described above is charged with ammonia, as refrigerant, water, as absorption liquid and hydrogen as inert gas, three cycles of circulation are set up, one for each of the fluids mentioned as follows:

Starting with the boiler the refrigerant passes upwardly through the conduit 11 into the gas separating chamber S then through the conduit 12 into the condenser C where it is liquefied and flows through the vessel 15 and the U-shaped conduit 17 into ther evaporator. In the evaporator the refrigerant is vaporized and conveyed by the inert gas through the conduit 21 into the lower compartment 23 of the gas heat exchanger, then through the pipe 30 into the absorber.

Being absorbed by the absorption liquid in the absorber, the refrigerant continues its cycle by owing back to the boiler through conduit 39.

The circuit for the absorption liquid is from the boiler B upwardly through the gas lift pump conduit l1, gas separating chamber S, conduit 38 into the top of the absorber. After trickling downwardly through the sections 32, 33 and 34 of the absorber the liquid will pass into the lower portion of the intermediate section 33 and from there flow to the conduit 39 back to the boiler.

The inert gas passes through a cycle starting with the evaporator E through conduit 21, compartment 23 of the gas heat exchanger and conduit 30 into the absorber, entering nrst the section 33. After passing upwardlyv acro the baille plates 37 therein the gas flows through the righthand leg of the inverted U-shaped conduit 13. From the right-hand leg ofthe gas conduit 13 the gas passes across the upper horizontal portion of pipe 13 and downwardly through the leithand leg of this pipe, then through the lower section 34; of the absorber, upwardly through the pipe 36 to vessel 35 and the upper section 32 of the absorber, through pipe 31, upwardly through the compartment 2d of the cylinder 18 and back to the evaporator through. the conduit 25.

The circulation of the inert gas is iniiuenced by the addition of heat from the pipe 12 to the gas passing upwardly in the right-hand leg of the inverted U-shaped conduit 13. The left-hand leg of this conduit, being exposed to the air is colder than the right-hand leg. Hence the gas therein is more dense and heavier so that the gases tend to circulate as the result of the force of gravity. This action may be accentuated if the left-hand leg of conduit 13 is cooled by some means.

In accordance with the present invention, the unevaporated liquid in the evaporator, which is of course quite cold, and the liquid collecting in the gas heat exchanger, are conveyed into heat transfer relation with the left-hand leg of the gas conduit 13. y

For this purpose, a drain pipe 50 is connected to the bottom' of the evaporator. Y'Ihis pipe passes downwardly along the left-hand leg of the conduit 13 and is then connected to the lower end of the vessel 33. Drain pipes 51 and 52 for the heat exchanger join the pipe 50 as it passes down along the leg of the gas conduit.

While only one embodiment of the invention has been shown and described herein it is apparent that various changes may be made inthe construction and arrangement of parts without departing from the spirit of the invention or the scope of the annexed claims. For example, in the claims, where a condenser'is called for, it 'will be understood that this term is broad enough to include a construction where a resorber is used for densifying the refrigerant, also where inert gas is recited it will be understood that this term includes condensable inert gases such as propane.

I claim: Y Y

1. In a continuous absorption refrigerating system, the combination of a condenser, an evaporator, an absorber and conduit means connecting the evaporator and the absorber to provide a path for the 4iow of. an inert gas in a cycle between the same, said conduit means including a conduit acting as a frame for supporting said condenser.

2. In a continuous absorption refrigerating system, the combination of a condenser, an evaporator, an absorber and onduit means connecting the evaporator ,and the absorber to provide a path for the now of an inert gas lin a cycle between the saine, said conduit means including an inverted U-shaped conduit acting as a frame for supporting said condenser. 3. In a continuous absorption refrigerating system the combination of a boiler, a condenser, an absorber, an evaporator, a conduit for conveying refrigerant gas from the boiler to the condenser and conduit means connecting the evaporator and the absorber to provide a path for the ow of an inert gas in a cycle between the same, said conduit means including an inverted U-shaped conduit acting as a frame for supporting said condenser and having one leg in heat exchange relation with said refrigerant gas conduit and. the other leg exposed to the atmosphere.

d. In a continuous absorption refrigerating system, the combination of a boiler, a condenser, an evaporator, an absorber, a conduit for conveying refrigerant gas from the boiler to the condenser', gas conduit means connecting the evaporator and the absorber to provide a path for the flow of inert gas in a cycle between the same means for circulating absorption liquid in a cycle between the absorber and the boiler and a drain conduit for conveying unevaporated liquid. from the evaporator to said absorption liquid circulating means said gas conduit means including an inverted il-shaped conduit having one leg in heat exchange relation with said drain conduit and one leg in heat exchange^ relation with said refrigerant gas conduit.

5. In va continuous absorption refrigerating system, the combination of a boiler, a condenser, an evaporator, an absorber, a conduit for conveying refrigerant gas from the boiler to the condenser, gas conduit means connecting the evaporator and the absorber to provide a path for the iiow of inert gas in a cycle between the same and including a gas heat exchanger, means for circulating absorption liquid in a cycle between the boiler and the absorber, a drain conduit for conveying liquid from the gas heat exchanger into the absorption liquid circulating means, said gas conduit means also including an inverted u -shaped conduit having one leg in heat exchange relation with said drain conduit andthe other leg in heat exchange relation with said refrigerant gasfconduit.

6. In a continuous absorption Yrefrigerating system having a number of inter-connected parts,

a gas conduit forming part ofa system for conveying gas in a cycle between certain of said parts, said conduit being of an inverted U-shape and acting as a frame for supporting certain parts of said system and means forl heating the gas in one leg of said conduit and for cooling the gas in the other leg thereof to facilitate circulation of the gas over itscycle. l

`'LY-In a continuous absorption refrigerating system, the combination of a boiler, a condenser, an absorber having a plurality of sections, an evaporator, means for conveying refrigerant gas from the boiler to the condenser, conduits connecting the evaporator to sections of the absorber and a conduit having vertically disposed legs connecting two of said sections together, all of said conduits cooperating to provide a path for Vthe flow of an inert gas in a cycle between the evaporator, the absorber sections, means for heating one leg of the conduit connecting two sections of the absorber and means for cooling another leg of the conduit connecting the two sections together to facilitate circulation of the inert gas over its cycle.

RUDOLPH s. NELSON. WAL'IER c. DAvmsoN. 

